Pat the pork tenderloin dry and season evenly with salt, pepper, chopped rosemary, thyme, and minced garlic.
Heat olive oil in a skillet over medium-high heat and sear the pork tenderloin on all sides until golden brown, about 2-3 minutes per side. Adjust heat to medium if needed and cook until the internal temperature reaches 145°F, about 10 minutes total. Let it rest for a few minutes before slicing.
Meanwhile, peel and dice the potato. Boil in salted water until tender, about 15 minutes. Drain and return to the pot.
Mash the potatoes with low-fat milk, unsalted butter, a pinch of salt, and a crushed garlic clove for extra flavor, until smooth and creamy.
For the carrots, peel and cut into sticks. Toss with a small drizzle of olive oil, salt, and pepper. Spread them on a baking sheet and roast in a preheated 425°F oven for about 20 minutes, or until tender and slightly caramelized.
Plate by layering a serving of creamy garlic mashed potatoes, topping with slices of the herb-seared pork tenderloin, and adding a side of sweet roasted carrots. Enjoy immediately.